This invention relates to disposable undergarments such as diaper covers or disposable diapers.
Japanese Patent Application Disclosure No. 1996-289902 describes a disposable diaper comprising a topsheet consisting of a central sheet and side sheets provided separately of the central sheet, a backsheet, a liquid-absorbent core disposed between these sheets, and a pair of barrier flaps in the form of side sheets longitudinally extending in the outer vicinity of transversely opposite side edges of the absorbent core.
Each of the side sheets comprises a proximal portion extending longitudinally of the diaper, an inner side portion extending transversely inward from the proximal portion and an outer side portion extending transversely outward from the proximal portion. The side sheets overlap the backsheet extending transversely outward from transversely opposite side edges of the central sheet and the side sheets have their inner surfaces joined to the upper surface of the backsheet. Longitudinally opposite ends of the respective side sheets are collapsed inwardly of the diaper and have their inner surfaces bonded to the upper surface of the topsheet.
In the vicinity of a distal end of the inner side portion, an elastic member is secured under tension to the inner side portion so as to extend longitudinally of the diaper so that the elastic member contracts to rise the inner side portion of the side sheet as the diaper is longitudinally curved with its inner surface inside.
In the case of the diaper described in the Japanese Patent Application Disclosure No. 1996-289902, the inner side portion of the side sheet is apt to move toward the upper surface of the central sheet. With a disadvantageous consequence, the side sheets may be risen insufficiently to prevent excretion from leaking beyond these side sheets.
It is an object of this invention to provide a disposable undergarment improved so that the barrier side flaps may be easily risen and thereby leakage of excretion may be reliably avoided.
According to this invention, there is provided an improvement in a disposable undergarment comprising sheet members contoured by transversely opposite and longitudinally extending side edges, longitudinally opposite and transversely extending ends and a pair of barrier side flaps extending longitudinally of the sheet members along the transversely opposite side edges and normally biased to be risen on an upper side of the sheet members.
According to this invention, the improvement is in that each of the barrier side flaps comprises a first side section extending above the upper side of the sheet members longitudinally thereof, a second side section extending below a lower side of the sheet members longitudinally thereof and longitudinally opposite end sections lying on the upper side of the sheet members at the longitudinally opposite ends thereof; the second side section includes a fold which extends longitudinally of the sheet members along which the second side section is folded back with an inner surface thereof put flat together so as to define a free subsection extending inward transversely of the sheet members and a fixed subsection extending outward transversely of the sheet members; and a surface of the fixed subsection opposed to the lower side of the sheet members is joined to the lower side and the longitudinally opposite end sections are collapsed inward transversely of the sheet members and joined to the upper side of the sheet members at the longitudinally opposite ends of the sheet members.
This invention includes an embodiment as follows:
The sheet members are provided with at least one barrier end flap extending transversely of the sheet members to cover at least one of the longitudinally opposite ends of the sheet members, the barrier end flap comprising a first section extending above the upper side of the sheet members transversely of the sheet members, a second section extending below the lower side of the sheet members transversely of the sheet members, and transversely opposite end sections lying on the upper side of the sheet members at the transversely opposite ends of at least one of the longitudinally opposite ends of the sheet members, wherein the second section includes a fold extending transversely of the sheet members along which the second section is folded back with an inner surface of the second section put flat together so as to define a free subsection extending outward transversely of the sheet members and a fixed subsection extending inward transversely of the sheet members and wherein a surface of the fixed subsection opposed to the lower surface of the sheet members is joined to the lower surface and the longitudinally opposite end sections are joined to the associated ones of the longitudinally opposite ends of the barrier side flaps.
With the disposable undergarment according to this invention, the barrier side flaps are normally biased to be spaced apart from the upper surface of the panel and such a biasing effect facilitates the barrier side flaps to rise on the upper surface of the panel. The topsheet cooperates with the distal side sections of the respective barrier side flaps to form the pockets opening inwardly of the panel as the barrier side flaps are risen. In this manner, leakage of excretion which would otherwise occur along the transversely opposite side edges of the panel can be reliably avoided.
With the disposable undergarment according to this invention which is additionally provided with a pair of the end flaps, the barrier end flaps also are normally biased to be spaced apart from the upper surface of the panel.
Consequently, such a biasing effect facilitates these barrier end flaps to rise on the upper surface of the panel. The topsheet cooperates with the distal sections of the respective barrier end flaps to form the pockets opening inwardly of the panel as the barrier end flaps are risen. In this manner, leakage of excretion which would otherwise occur along the transversely opposite side edges as well as along the longitudinally opposite ends of the panel can be reliably avoided.